Pen-arm-adjusting mechanism for recording instruments.



- B. HODGKINSON.

PEN ABM ADJUSTING MECHANISM FOR RECORDING INSTRUMENTS.

PPPPPPPPPPPPPPPPPPPPPPPPP 1. 1,060,761. Patented May 6, 1913.

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ti. HODGKINSON.

PEN ARM ADJUSTING MECHANISM FOR RECORDING INSTRUMENTS APPLICATION FILED JULY 5, 1911.

1,060,761. Patnted ma 6, 1913.

'2 sums-511mm.

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EDWIN HODGKINSON, OF BOOHTISTER,v NEW YORK, ASSIGNOR TO TAYLOR INSTRUI I ENT COMPANIES, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

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Specification of Itetters Patent.

Patented May 6, 1913.

ori inal application flied 0mm 3, 1910, Serial no.-5as,o14. Divided and this application filed July 5,

1911. Serial No. esaoio.

To all whom it may concern:.

Be it known that I, EDWIN HODGKINSON, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Pen-Arm- Adjusting Mechanism for Recordinglnstruments; and I do hereby declare the followilig to be a full, clear, and exact description 0 the same, reference being had to the accompanying drawings, forming a art of this specification, and to the re erencenumerals marked thereon.

My present invention relates to instruments used for indicating or recording temperatures or pressures, and particularly to those in which a continuous record is made by means of a stylus cooperating with a continuously moving surface or recording sheet.

In this connection my invention has for its object to provide an improved means for mounting and operating a stylus or pen arm whereb the latter maybe conveniently adjusted initially and corrected in relation to the chart or recording sheet.

To these and other ends the invention consists in certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification. I

In the drawings: Figure 1 is an enlarged front elevation showing in detail the mechanism employed for operating and adjusting a stylus, part of the outer casing being shown in section; Fig. 2 is a side elevation of the parts illustrated in Fig. 1; Fig. 3 is a sectional view taken on the line 3"--3" of Fig. 1 looking in. the direction indicated by the arrows, and Fi 4 is a detail sectional view taken on the line 4.4" of Fig. 1.

Similar reference numerals throughout the several figures indicate the same parts.

This application is a divison of m prior application, Serial No. 585,014, filed .ctober 3, 1910, for indicator and recorder.

In illustrating my present invention I have shown it in connectionwith a telethermometer, an instrument used for indicating and recording continuously temperatures which are maintained for given periods of time in carrying out diflerent processes of manufacture, such as in enameling ovens, cooking vats, kettles, or the-like. I

Generally the apparatus comprises a casing 1 mounted upon thebackmg 2 which may be secured to any convenient sup ort, the front of the casing being closed y a door 3 provided with a glass panel. Within the caslng is a clock train preferably protected by a coverin 4 through which the drivenarbor 5 oft e clock train vprojects, and on which is detachably secured a metal disk 6 held in place by a thumb screw 7 adapted to support the removable recording sheet or chart indicated by 8 provided with suitable lines or graduations.

It is essential in an apparatus of this character that a means be provided for adjusting the stylus relatively to the zero point or line of the scale, or to some other arbitrary division thereon in the first instance, and

when so adjusted that it will be capable of continued accurate operation. In the illus-.

trations showing the preferred embodiment of my invention, the arm A, supporting the stylus, is a light sprin connected at its lower end to a plate a rigid y attached to an arbor a. The latter is journaled in a swinging or rocking frame comprising the front and rear pieces 6, f, the latter having a downwardly extending end f, pivoted on a screw 7 secured in a post i projecting forwardly from the supporting plate 2. The frame pieces 6, f, are separated by spacing members g, g, and one end of the frame piece e projects laterally, as indicated by e, where it is slotted to accommodate an adjusting screw it, the lower end of which is threaded in the outer end of the bracket 21. The upper end of the screw is arranged in proximity to the lower edge of the door opening in the casing where access may be conveniently had to it. The screw is also provided with a shoulder which engages the upper edge-of the arm e with which the latter is held in contact by a coil spring is, its upper end being inclosed in a cap is. From t is arrangement of the parts it will be observed that by rotating the screw in one direction or the other the arm 6 will be depressed to rock the frame mercury, which, when affected by tempera ture, will impart to the spiral B a tendency to straighten out,-as will be. understood. It will be understood, however, that the spiral B may be a Bourdon tube, in which eventthe shank B will be connected to the source of pressure supply, such as a steam or air pipe, the variations of pressure in which will cause the curved tube 'to distend or con-- tract am thus impart movement to the stylus.

An articulated connection isprovided between the arm A and the spiral or active end of the capillary tube com rising a link a, which is pivoted to the en of the arms and to a post or projection 6 attached to the outer convolutlon of the spiral B. In forming this operating connection .I provided therein means for accomplishing two adjustments of the stylus, both of which are inde pendent of the swinging of the arbor a around its pivotal support f by means of the set screw 71,. In carrying out this feature of my invention instead of connecting the arm a directly to the arm A, I interpose between these parts a slotted link a which is held in adjusted position by a set screw a, the lower end of the link forming an extension of the arm A, and adjustable vertically relatively to the pivot a .for the purpose of determining the amplitude of the movement to be given the stylus, which it will be understood depends upon the range through which'the instrument is adapted to operate, and dependent upon the amount of movement which it is expected to obtain in the active end or spiral B of the capillary tube. This adjustment also affords a means of setting the stylus for making records upon charts of ditferentsizes or chart sheets having different forms of graduations. The second adjustment, referred to above, operates in conjunction with the shifting action of the pivot a and is accomplished by making the arms a, in two parts, the second part comprising the link a (Fig. 3) both the latter and the part a being slotted and overlappingand rigidly clamped together by set screws a 'carried in a clamping plate a a. By loosening the screws a the length of the arm may be increased ordiminished to-position the pen point or stylus in the approximate position desired in reference to the'zero lineorany othergraduation' onthe chart, and should it be necessary to after- An ,adjusting mechanism embodying myinvention is simple in construction and cousisting of few parts which may be readily assembled, the several elements being designed and arranged to afford a means of readily and accurately positioning the pen relatively to the chart.

\ I claim as my invention:

1. In a recording instrument, the combination with a support, a movable chart and a pressure actuated member having an acthe portion, of a pivoted arm having astylus cooperating with the chart, a member connecting said active portion and said arm for imparting movement from the former to the latter, an adjustable cradle sup-- porting the pivot of the arm and an adjusting member carried on the support and cooperating with the cradle for shifting the position of the pivot and moving the arm relatively to the chart.

2. In a recording instrument, the combination with a support, a movable chart and a pressure actuated member having an active portion, ofan arm pivoted to the support having a stylus engaging the chart, an

operating. connectionbetween the arm and said active portion, a movable cradle carrying the pivot of the arm, a finger on the cradle and an adjusting screw cooperating with the support and finger for shifting the position of the cradle to vary the position of the pivotal point of the arm.

3. In a recording instrument, the combination with a support, a movable chart and a pressure actuated member having anactive portion, of a cradle pivoted to the support, a stylus arm pivoted on the cradle, the

pivotal points of the cradle and arm being ofl'set re atively to each other, an operating connection between the arm and said active portion and means for adjusting the cradle in its pivot to shift the position of the pivot of the stylus.

4. In a recording instrument, the combination with a support, a movable chart and a pressure actuated member having an active portion, of a carriage movably mountedon the support, a stylus arm pivoted on the carriage, an operating connection be tween said arm and said active portion, and means for shifting the carriage to adjust the pivotal point of the arm relatively to said tion between the member and arm for swing active portion to rock .the arm in one dlrecing the latter relatively to the chart and tion or the other. means for shifting the frame to alter the po- 5. In arecording instrument, the combisition of the pivot point of the arm.

5 nation with a support, a chart, an operat- 7 In a recording instrument, the combi- I ing member having a part adapted to be nation with a support, the active spirally actuated by fluid under pressure, of a rockwound end of a fluid pressure operated tube ing frame pivoted on the support, an .-indimounted on the support, a frame piece ad- ,cating arm pivoted on the frame and cojustably held on the support and a stylus 10 operating with said chart, a laterally extendarm journaled on the frame, of a rigid 0p-" ing arm on said frame, an adjusting screw erating connection attached to the arm at cooperating with the arm and threaded in one side of its pivot and connected to said I the supportto shift the arm relatively to the end of the tube and means for shifting the chart, and an operating connection between frame to move the pivot of the arm rela- 15 said member and arm. tively toward and from said tube.

6. In a recording instrument the combi-. nation with a support and a mdvable chart, I EDWIN- HODGLINSON' an operating member and an adjustable Witnesses bearing frame, and an indicating arm piv- HENRY S. KIMMEL, 20 oted on the latter, of an adjustable connec- CURTIs D. HART. 

